FBI Buildings did a great job for my ex-FIL but that has been 20 years ago. I have no recent info to give but I doubt they have strayed from the tried and true. We saved a bunch of money by me doing all the backhoe and skid steer work. He used a commercial concrete company come in to pour the cement as I had scheduled overtime coming up.
I had one built by Miller Building of Amboy, IN. They are an Amish company builds a majority of the post frame buildings in this part of the state. Reach out to them and they may do it or recommend someone in the location where you want to build.
The only one here that we didn't build ourselves is an FBI building. No complaints. They are very professional, put up a good building and cleaned up any mess. They are not cheap. Morton Buildings is another one that would likely do a good job for you. I'm not familiar with any of the others around.